Preparation of novel polypyridyl ruthenium complex polymers with high sensitivity for electrogenerated chemiluminescenceviacopolymerization

Abstract

We report two novel monomers, Ru1mono with one vinyl group, 4-[(4-vinylbenzylformamidyl)-4′-carboxylacid-2,2′-bipyridyl]-bis[2,2′-bipyridyl] ruthenium(II) perchlorate and Ru2mono with two vinyl groups, 4,4′-bis[(4-vinylbenzylformamidyl)-2,2′-bipyridyl]-bis[2,2′-bipyridyl] ruthenium(II) perchlorate. The molecular structures were demonstrated by NMR, mass spectrometry and elemental analysis. Polymers Ru1MVP and Ru2MVP were then co-polymerized under free radical polymerization from Ru1mono or Ru2mono and 4-vinylpyridine with the molar ratio of 9 : 1, respectively. Electrogenerated chemiluminescence (ECL) of Ru1MVP in a thin film on an electrode has been tested. It increased 17 times relative to cis-[Ru(bpy)₂PVP₁₀](ClO₄)₂ (RuPVP) reported in the presence of co-reactant tri-n-propylamine (TPA) at the oxidative peak around 1.16 V with scan rate of 100 mV s⁻¹. Relative to RuPVP ECL of Ru2MVP was 110 times greater with TPA, and 40 times greater with another co-reactant, sodium oxalate. The significant enhancement of ECL and improvement in making a stable film could be expected to lead to an applicable immobilized immunoassay technology via ECL.